Microstructures having deformable elements, such as microelectromechanical devices may suffer from device failure when the deformable elements experience plastic deformation that exceeds a tolerable amount. For example, a micromirror-based spatial light modulator is a type of microelectromechanical device and comprises an array of micromirrors. Each micromirror has a mirror plate attached to a hinge such that the mirror plate can rotate. In operation, the mirror plate rotates in responses to an electrostatic field, and the hinge deforms. Mechanical properties of the deformable hinge and the attachment of the hinge to the mirror plate determine the operation of the micromirror and thus, the performance of the spatial light modulator.
Therefore, a method is desired to process the deformable element of the microstructure for reducing the plastic deformation during operation so as to improve the life time of the microstructure.